The Effect of Bottle PEP Exercise on Expiratory Muscle Thickness, Strength, and Balance Parameters in Parkinson's Disease Patients

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by rigidity, tremor, postural instability, bradykinesia, and autonomic dysfunction. It is a common movement disorder worldwide. Motor impairments in PD patients are not limited to the muscles of the extremities; the neck, upper respiratory tract, and respiratory muscles are also affected. The resulting pulmonary dysfunction is one of the main factors contributing to morbidity and mortality in PD patients. Respiratory muscle exercise programs have been used to improve lung and swallowing function in patients with Parkinson's disease and other similar neurodegenerative disorders. Studies of inspiratory muscle exercise in Parkinson's patients have reported improvements in inspiratory muscle strength and endurance. Similarly, expiratory muscle exercise protocols have been shown to increase maximum expiratory pressure (MEP) and cough effectiveness. However, studies on expiratory muscle strengthening are lacking in the literature. Positive expiratory pressure (PEP) devices are used to clear airway secretions and feature a resistance that provides resistance during exhalation. This creates a positive pressure that stabilizes the airways during exhalation and prevents airway collapse. Although there are many PEP devices available on the market, the bottle-PEP, a therapist-made device, is used because it can be produced easily and at low cost. The bottle-PEP device consists of a bottle filled with at least 10 cm of water and a tube placed inside the bottle. Although information on strengthening expiratory muscles is traditionally found in the literature, there is no data in the literature on the effect of bottle-PEP use on expiratory muscle strength, especially in Parkinson's patients. A review of the literature shows that the effect of expiratory strengthening on balance has not been studied before. This study aimed to demonstrate the effects of the bottle-PEP device, used in addition to expiratory muscle strengthening, on expiratory muscle thickness, strength, and balance.